OSAT Biological Sciences (110) Practice Exam 2026 - Free Biology Practice Questions and Study Guide

The correct answer is that both statements A and B are true regarding speciation.

Allopatric speciation involves the formation of new species through geographic isolation. This typically occurs when a physical barrier, such as a mountain range or a body of water, divides a population, preventing members from interbreeding. Over time, the isolated populations may undergo genetic divergence due to natural selection, mutation, and genetic drift, ultimately leading to the emergence of distinct species.

Sympatric speciation, on the other hand, occurs when new species arise within the same geographic area. This type of speciation can happen due to various mechanisms such as polyploidy in plants, behavioral changes in mating preferences, or differences in resource utilization that lead to reproductive isolation despite the absence of physical barriers.

Both processes highlight the diverse mechanisms through which speciation can occur, affirming that the statements about allopatric and sympatric speciation are indeed correct.